TGS, formerly TGS NOPEC Geophysical Company ASA is an energy data and analytics company. It gathers, interprets, and markets seismic and geophysical data regarding subsurface terrains worldwide in order to evaluate oil and gas formations for drilling operations. TGS is listed on the Oslo Stock Exchange, was founded by a 1998 merger of TGS (Tomlinson Geophysical Services Inc.), Calibre Geophysical Co. Inc (founded in 1981), and NOPEC (Norwegian Petroleum Exploration Consultants) International ASA founded in 1981, with financial headquarters in Oslo, Norway and operational headquarters in Houston, Texas. The Company is led by CEO Kristian Johansen with nearly 2,000 employees around the globe with main offices located in Oslo, Houston, London, Rio de Janeiro and Perth.